The only cover crops that are inoculant oriented are the legumes. It isn't an issue with the many other cover crops. And the effectiveness of inoculants, even with legumes, is debated as their only "claimed" purpose is to improve growth rates and plant health. Some swear by them, others consider them a waste of money since it is perfectly possible to grow legume crops without the use of inoculants. It all depends on the level of microbial activity already in your soil.

That said, if a legume cover crop is what you choose to use then unless you are seeding an exceptionally large area, have very poor soil with documented low bacterial counts, cost is no object, and you simply must have maximum production I wouldn't worry about inoculants.

They pose no treat to your "organic soil" and are merely high doses of normal soil bacteria and can be either mixed into the soil itself prior to seeding or mixed into the raw seed before scatter-sewing it.

Hope this helps.

Dave

Diane I think it may be too late in zone 5 to plant cover crops now?

In your zone, it's most likely too late for this, but I highly recommend Crimson Clover as a cover crop. It's an attractive annual clover, so not invasive. I turn it under when it blooms - or even sooner if you are ready to put in your veggie crops.

Also check your nearest co-op for seed. I pay about $4.00 for a pound of tillage radish seed.